monotonous[单调的]/boring/dreary/dull/humdrum/repetitious/tedious

-eg: Job-hopping means a broad range of work and life experience rather than monotonous life.;

reward[报酬/奖赏]-rewardless[徒劳的]，

reward for[作为..奖励]，

reward and punishment奖惩

probation[试用/见习]/test/trial/apprenticeship，

[补充]probationer/probie/trainee/novice/apprentice，

probation period[试用期]，

be on probation[试用];

employee[雇员]/staff/wage-earner;

be out of job[失业的]/unemployed/jobless/redundant/on the dole

undertake[承担/从事]

- eg: I'll undertake for your security in the concert.;

hold top position[事业高峰]

- eg: The majority of stars cann't hold their top position if they stop finding breakthrough in their careers.;

for the good of[为了...好]。